This invention relates to the preparation of pentachloropyridine by the chlorination of compounds containing a pyridine ring nucleus and to compounds of this type.
Pentachloropyridine is a well-known chemical intermediate with many industrial applications. It is generally prepared by the chlorination of pyridine, picolines or lutidines or of partially chlorinated pyridine, picoline or lutidine compounds at relatively high temperatures, sometimes in the presence of Lewis acid catalysts. Many such methods are summarized in the book, Polychloroaromatic Compounds by Suschitzki, Plenum Press, 1974, pages 225-231. The discovery of methods of preparing pentachloropyridine by simple processes from cheap and available starting materials, however, is of continuing interest.